Fuse block and parts thereof



May 16, 1939. H ,1 1 FRANK 2,158,655

FUSE BLOCK AND PARTS THEREOF' lig. 2

INVENTOR.

ATTORNEY.

WMM M May 16, 1939. H. J. L. FRANK 2,158,655

Fusi: BLOCK AND PARTS THEREOF i Filed Feb. .'5, 1938 5 Sheets-Sheet 2 mi Z3 i 1 y, /Zg z- 2af A 1 F .an

V 2k3/@f M INVENTOR B ATTORNEY.

May 16 1939 H. J. l.. FRANK 2,158,655

FUSE BLOCK AND PARTS THEREOF Filed Feb. 3, 1938 IN VENT OR.

BY gw ATTORNEY. v

5 sheets-sheet 3 May 16, 1939.

J. AFRA-M( 2,158,655

FUSE BLOCK AND PARTS THEREOF Filed Feb. 5, 1938 5 Sheets-Sheet 4 ATTORNEY.

May 16, 1939- H. J. L. F-RANK 2,158,555

FUSE BLOCK AND PARTS THEREOF Filed Feb. 5, 1958 5 Sheets-Sheet 5 /O al 7 /0 /a f4 o l 4 z \f/ #L /l/ 2 l /4 I o S17/i2? l 4 Jug 1a INVENTOR BM f T' ,V7

"'WTTORNEY.

Patented May 16, 1939 UNITED STATES PATENT CFFICE FUSE BLOCK AND PARTS THEREOF Harrison J. L. Frank, Detroit, Mich.

Application February 3, 1938, Serial No. 188,501

" 12 Claims. I (Cl. 200-133) 'I'he inventions of this application relate to fuse blocks and parts thereof and particularly to fuse blocks formed for receiving plug fuses.

Generally speaking, the inventions hereof relate to the type of fuse block that comprises a block of insulating material mounting a bus bar to whicha line conductor is connected: in the block is provided a socket or depression containing a screw shell for the reception of a plug fuse: a branch conductor is mechanically and electrically connected to the screw shell and the circuit is established between the line conductor and the branch conductor through the bus bar, the plug fuse, and the screw shell.

One invention aims to provide a construction wherein electrical connection between the plug fuse and the bus bar is established by direct engagement between the bus bar and the tip contact of the plug fuse.

Another invention aims to provide a novel mechanical and electrical connection between the terminal of the branch conductor and the screw shell, with such connection being established by the action of threading the plug fuse into the screw shell. Y

Still other inventions aim to provide novel details of construction of fuse blocks.

The inventions hereof will best be understood' by reference to the following description of the embodiments thereof that are shown in the appended drawings. In these drawings,

Fig. 1 is a top plan view of a fuse block of the invention, with one of the two sockets shown as equipped with a plug fuse and with parts cut away for purposes of clarity;

Fig. 2 is a section on line 2 2 of Fig. l;

Figs. 3, 3a and 3b are sections on line 3 3 of Fig. 1, but showing the parts in their various positions;

Figs. 4 and 4a are views of modified forms of screw shells;

Fig. 5 is a plan view of a modification;

Figs. 6 and 6a are cutaway viewsof this modication with the parts shown in their various positions.

Fig. 7 is a plan view of still another modification;

Figs. 8 and 8a are cut away views of this modication with the parts shown in their various positions;

Fig` 9 shows a resiliently formed bus bar and a modied form of screw shell.

Figs. 10-12 are views of a modification with the parts in their various relative positions,

Figs. 13-14 are sections on lines I3-I3, IIL-I4, of Figs. l0 and 12 respectively.

Referring to the drawings, and morev particularly to Figs. 1-3, it will be observed that these figures show a fuse block I0 of insulation material in whose top surface are formed round sockets II, each containing a screw shell I2. Through four aligned holes I4 of two of such screw shells is passed an abutment in the nature of a bus bar I5 to an end of which is connected, by a suitable connection means I6, a line conductor I1.

Formed in the two screw shells at angles 'iii 90 with respect t0 the line of the holes Il' are two additional holes 20 aligned with two holes 2| formed in the side edge of the block for the reception of the terminals 22 of branch circuit conductors 23, which when entered into the screw shells through the holes 2| and 20 will dispose themselves under the bus bar I5 and at right angles thereto.

Suitable insulation means insulates the branch circuit conductor terminals 22 from the bus bar I5. In the embodiments shown such insulation means comprises a U-shaped sleeve 24 disposed around the bus bar and engaging the bottom and side edges of the bus bar, Other insulating means, such as sleeves'on the terminals 22, where they are directly in linewith the bus bar, might also be used.

When the parts are associated as shown in the drawings, Fig. 1, lower part of Fig. 2, and Fig. 3, with the terminals 22 under,- transverse of,` spaced from, and in line with the bus bar I5, and with these passing through the holes I4 of the shells I2, and with the ends of the bus bar resting on the two block ledges 25 and secured with respeci; to the block by the screw 26, the act of threading a plug fuse 2T into a screw shell will serve to eiect proper mechanical and electrical connection of the parts. The plug fuse tip 28 will rst engagethe topor bar surface of the bus bar to effect electrical connection between the plug fuse and the bus bar, and, consequently, between the bus bar and the screw shell, through the fuse, and will then pull the screw shell upwardly from the position of Fig. 3 to that of Fig. 3a and then to that of Fig. 3b, wherein the lower edge of the hole 20 of the screw shell will bite into the terminal 22, and with this terminal kinked as shown at Fig. 3b to be properly interlocked to the screw shell and properly pressed against the bottom of the screw shell to effect mechanical and electrical connection between the branch conductor and the screw shell, with the net result that all the parts are thinly secured in the bloei; and proper electrical connection from the line conductor il to the branch conductor through the plug fuse is established.

Whereas in the modification of Figs. l-l each screw shell is shown as having but one hole il@ for the reception oi a terminal as an alternative the expedient shown in l may be utirlhis figure shows each screw shell as having two aligned holes 2@ through which the terrninal is passed and, as shown in Fig. ll, the 'threading in oi the 'plug fuse into the shell will provide a double hint; in each terminal and a mul" "e point engagement o the terminal with ew shell holes will also be observed that the engagement e terminal with the bottom edge o the shell hole or holes il@ is in the nature oi lng engagement, such bottoni edge oi the d cutting through any film that may iineliist on the terminal lied, the hole 2li may be formed as shown la, tapered to provide a large part receivinal and a small part into which such may be wedged, as shown.

.and 6 show a modification wherein the l l ell is in the form oi a strap Such strap comprises a bottom part 3i and t vo side parts oil whose tree edges are provided with inin tips 3C having terior parts 33 terminating tongues Sli on their ends fitting in holes o stvofo side parts 32. Threads are 'formed the lacing surfaces-oi the interior parte 3S i 'threaded cooperation with the plug 2l. inlrs :termed in the. bottoni part Si irl the tips 3d ior biting engagement with a terlil thrust into the strap through the ned holes 3G formed in the sides the Sii-fai?.

llt will be observed that when a terminal 22 is rist into a strap through a block hole Zi and e strap holes 3G and thereafter a 'plug fuse 2l tl leaded into the strap, cooperating with the threads, that the tip Ziller the fuse will engage e bus par le and pull up on the strap and at e time move the interior parts 33 and eir 35' into the position of Fig. 6a trom o 6 to cause the kinks in the tips and in 'the bottoni o the strap to bite into the terminal and elect good binding contact between the terminal and the strap. At Ell will wedge into holes d@ and bind terminals B2 in these holes.

llt will also be observed that the socket il in which is disposed the strap 3l] has side slots 3Q receiving the side parts 3Q of the strap. The disposition o the side parts or the strap in the side slots ci? the socket eliminates the possibility of objectionable relative sidewise Shifting of the strap and the block.

lt will be observed that the tunnel between tip 35i and the shell bottom Si is in effect a continuation of the side hole 36 and that tip Sil is in eect a side edge or wall of such tunnel.

lt will also be observed that in any embodirrent here shown there are clear side spaces in the shell through which the bus bar and conductor pass. Holes lli and the spaces between parts 33 are such spaces; and holes 2U and 38, as well as the tunnels between parts 3i and 34, are also such spaces. f

lt will also be observed that while the abutment, with respect to which the screw shell i2 is moved relatively, is shown as a bus bar i5, it need not be such, but may be any suitable means;

the same time, tongues entente for example, it may be a terminal of a conventional insulated wire.

Further, that in the abutment (bus bar) lli and the terminal function to prevent rotation of the shell it in the socket il.

in the modification shown in Figs. il-ii, which modification closely resembles that oi l Is. ii, the tongues Sil are shown as formed with e sions di adapted to engage strap parte 322 to l inward motion of the threaded parte s these parts are spread apart by the spread cone of a plug fuse the part "li actin@ l l tive stops. Further, there are shown to bent downwardly from the strap and n' with holes through which pass the termina arrangement shown, the

These tongues provide a positive interlocl;y he tween the strap parts and the termi l 'fo al d prevent axial separation of these tively.

'it will also be noted that the bloei: l@ ii i'orn'iedto provide a recess d surface f1.3 for seating the free ends of the ser minal lt will also be ole-served that in this modification the bloeh7 side slots are :formed with ribs which closely hug the lower ends o the stro; parts and thus aid in preventing these strap parts from twisting out oi shape and helps loot; these parts in position.

in the modification of Fig. 9, which o resembles that of l to 4, the bus i s shown as provided with a cutout (39 in which is disposed a copper leaf suing o corrugated -icrrn and having its ends secured to the bus bar to provide a resilient seat ior the plug fuse and thus to resiliently clamp the latter against rotation for loosening in the shell lil and at the same time to provide a resilient clamp on the wire terminal 2li.

ln addition., the screw shell is shown as prou vided with tongues El which seat within sockets ormed in the main socket il o the bloeit, the tongues cooperating with the side walls oi' the supplementary sockets 52 to aid in limiting twisting oi' the screw Shell in the soclret il.

ln assembling the parts, the shells are placed in their soclrets, the bus bars are passed through the blocks and the shells to hold the shells in place, the screws il@ are then threaded home to fasten the bus bars in place, then the terminals 22 are passed through the blocks and into the shells, and Finally the fuses are threaded home to fasten the terminals in place and to bind them into electrical engagement with all the parts.

'inthe modification ci Figs. lil-14, the bottom o the screw shell l2 is perforated, as at 60, to receive the bent part 6l of a springy washer or strap 62 formed as shown, to interlock `ythe terminal t2 and the screw shell, when the terminal is threaded through the shell holes 20 and the washer bend 6 i and lies in the transverse grooves of the shell bottom. Threading a plug fuse ill down into the shell pulls up on the shell, washer, and terminal, until the tip 28 engages the bus bar i5, and the washer engages the insulation 24 around the'bus bar.

Now having described the fuse block hereof in its various embodiments and the inventions hereof as embodied in the device shown in the appended drawings, reference/will be had to the claims which follow for a determination of the inventions.

l claim:

, l. A block having a socket, a screw shell therein, a bus bar passing through a hole in a side of the shell and insulated from the shell, a conductor passing through another hole in the shell and passing transversely under and insulated from the busv bar, whereby a tip and sleeve contact device threaded into the shell will have its tip engage the bus bar and cause relative movement of the bus bar, the shell, and the conductor with the conductor engaging and making electrical contact with the shell and kept out of electrical contact with the bus bar.

2. A block having a screw shell, a bus bar passing through a clear side space of the shell, a conductor also passing through a clear side space of the shell, with the bus bar between the conductor and the open end of the shell, and with the bus bar insulated from the shell and the conductor, whereby a tip and sleeve contact type device, whenvthreaded into the shell, will have its tip contact engage the bus bar to cause relative movement of` the bus bar, the shell, and the conductor, with the shell and the conductor making mechanical and electrical contact with each other, and with the bus bar making insulated mechanical contact with the shell and con--v ductor, and with the sleeve contact of the device making mechanical and electrical contact with the shell.

3. In combination, a screw shell khaving a side hole, a conductor terminal therein, an abutment in the shell, and a tip and sleeve contact device t for threading into the shell and engaging the abutment and moving the shell and conductor relatively to bind the conductor against an edge of the side hole.

4. In combination, a screw shell having a side hole, a conductor terminal therein, an abutment in the shell, and a tip and sleeve contact device for threading into the shell and engaging the abutment and moving the shell and conductor relatively to bind the conductor against an edge of the side hole, with the conductor also bound between the shell and the abutment.

5. In combination, a screw shell having a side hole, a conductor terminal therein, an abutment in the shell, and a tip and sleeve contact device for threading into the shell and engaging the abutment and moving the shell and conductor relatively to bind the conductor against an edge of the side hole, with electrical contact between the conductor and shell, between the shell and the side of the device, and between the tip of the device and the abutment, and means i'or insulating the abutment from the shell and conductor.

- 6. In combination, a screw shell having a side hole, a conductor terminal therein, an abutment in the shell, and a tip and sleeve contact device for threading into the shell and engaging the abutment and moving the shell and conductor relatively to bind the conductor against an edge of the side hole, with the conductor also bound f between the shell and the abutment, with electrical contact between the conductor and shell, g

between the shell and the side of the device, and between the tip of the device and the abutment. andmeans for .insulating the abutment iroml shell and conductor. 7. In combination, a screw shell having a side hole, aconductor terminal therein, an abutment in the shell, and a tip and sleeve contact device for threading into the shell and engaging the abutment and moving the shell and conductor relatively to bind the conductor against a flanged edge of the side hole.

8. In combination, a screw shell having a side hole, a conductor terminal therein, an abutment in the shell, and a tip and sleeve contact device for threading into the shell and engaging the abutment and moving the shell and conductor relatively to bindthe conductor against a flanged edge of the side hole, with the conductor also bound between the shell and the abutment.

9. In combination, a screw shell having a side hole, a conductor terminal therein, an abutment in the shell, and a tip and sleeve contact device for threading into the shell and engaging the abutment and moving the shell and conductor relatively to bind the conductor against a flanged edge of the side hole, with electrical contact between the conductor and shell, between the shell and the side of the device, and between the tip of the device and the abutment, and means for in- .sulating the -abutment from the shell and conductor.

10. In combination, a screw shell having a side hole, a conductor terminal therein, an abutment in the shell, and a tip and sleeve contact device for threading into the shell and engaging the abutment and moving the shell and conductor relatively to bind the conductor against a flanged edge of the side hole, with the conductor also bound between the shell and the abutment, with electrical contact between the conductor and shell, between the shell and the side of the device,

and between the tip of the device and the abut- I ment, and means for insulating the abutment from the shell and conductor.

1l. A screw shell, a conductor passing through a hole in a side of the shell and insulated from the shell, a conductor passing through another hole in the shell and passing transversely under and insulated from the rst mentioned conduc tor, whereby a tip and sleeve contact device threaded into the shell will have its tip engage the first mentioned conductor and cause rela.- tive movement of the shell, and the two conductors, with the second mentioned conductor engaging and making. electrical contact with the shell and kept out oi' electrical ,contact with the first mentioned conductor.

12.A screw shell, a conductor passing through a clear side space of the shell, a second conductor also passing through a clear side space of the shell, with the rst conductor between the second conductor and the open end of the shell, and with the first conductor insulated from the shell and the second conductor, whereby a tip and sleevecontact type device, when threaded into the shell, will have its tip contact engage the first conductor to cause relativemovement of the shell, and the two conductors, with the shell and the second conductor making mechanical and electrical contact with each other, and with the irst conductor making insulated mechanical contact with the shell andsecond conductor,

and with the sleeve contact of the device making 

